still not starting

[rhyatt]

Strange , you do get sparks across the plug ? I think you said you do.
So back to basics , decent compression , valves opening and closing , valve clearances of course.
Dare I assume the spark is in the right place  and timing not slipped.

[Barnsey]

Yes I had a spark.  I didn't get time to check it today, but I will. Family life means I get the odd half hour here and there. 

Since the bike was running prior to fitting the loom, timing and compression shouldn't be issues but I think I am at the point that I need to start checking these things too. 

That said I don't think compression is an issue.  It is much harder to kick over with the plug in than out and it makes the right sort of chuff chuff noises. 

  I will also look at some of the other suggestions.  As I say, family & work prevent me doing everything in one session, but I value all suggestions and will get around to trying everything. 

[Barnsey]

BTW...

     I kicked it over with the plug out. There is a regular spark on the plug, even turning over slowly on the kickstart by hand.  So I don't think the coil voltage is an issue now. 
The plug was wet when I took it out.
The previous owner, helpfully, put a timing mark on the points in red paint, and it hasn't moved. 
I checked the wiring on the ignition switch and it is entirely consistent with the wiring diagram for an early bike.
Buzzing out the switch sowed it to be correct.

   Ian

[Barnsey]

Silly question, I know, but I am new to old Brit Bikes,  can I flood the bike and keep it from starting through over tickling it?  My guess is no, as the carb bow will be lower than the manifold if the designer had any sense. 

I generally tickle until I get fuel coming out of the overflow in the button, and I am assuming this is the correct thing to do. 

[rhyatt]

My ss80 will not start if I tickle it too much and use the choke.
Then I have to take the choke off , twistgrip WIDE open and start kicking , it'll go then , roughly then clears.
Are you tickling till floods and choke as well ?
Different times of year demand different amounts of tickle and choke !!

[Barnsey]

No choke on my bike, only tickler, but I will try tickling it a little less.   I have tried with a little throttle too, but no result. 

[Kernowpete2]

Have you tried no tickle? I'd want to start off lean (no tickle) and richen it progressively until it fires. That way you can avoid flooding it and figure out whats right rather than hoping you randomly hit the spot without flooding it (if that makes sense???).
Start with a dry plug and kick the bike over several times with the plug out and the throttle wide open to clear it.

[Barnsey]

Good plan!  I'll try that out and report back later today!  Thanks

[Kernowpete2]

Good luck. Take your time. There's some logic in it somewhere!

[iansoady]

You say the plug is wet which definitely suggests over-tickling. The level in the float chamber can easily get so high that neat fuel is dripping into the inlet tract when tickled. I'd agree with KernowPete2.

[scifi]

My Ossa MAR is a pig to start at the start of a trial.  It has a Monobloc carb and requires the tickler to be pressed a further 20 seconds after the fuel comes out, to put some fuel into the crankcase.   Once it has started that way in the morning, it fires up perfectly every time with no tickle, for the rest of the day.   I have some bikes with the Mikuni carbs, and they are simplicity themselves, with just the richening plunger raised.
I think Amal didn't really do a good job for cold starts, even the Villiers carbs had a nifty sliding choke on the air filter, which was very efficient.

[Barnsey]

Sorry if I am not a carb connoisseur but I was recommenced to replaced the stock carb with the larger Amal with choke,  but, to my annoyance, it didn't fit between the engine and the air box on my stock bike. SO it got sent back.

  If anyone can recommend a carb which is reliable and cheap and will fit a stock bike then I am all ears.

Right now I am being distrated by a leak in the fuel tap.

This is a side issue, so I will start a new thread.   

[Steve.S]

Lots of excellent advice here. I hope you get time to take it all on board, but you seem to have bypassed some of the suggestions.
Could I ask if your 5 volts at the coil is with the points open or closed?
Just laying the plug on the head won't tell you anything very much. You need to do a spark gap test, as already suggested.
Sounds like you're flooding it. Heat the spark plug, and try it again.

[Barnsey]

Yep,  5 V with the points closed.  Holding the points open with a cable tie gives me the full voltage.  It is still losing a volt somewhere, probably in the switch.  I can certainly try bypassing the switch with a negative wire direct to the coil.   Should I really need the full 6V?

  Flooding?   Yes, I was in the process of looking at this when the fuel leak distracted me.  Kick it over with the plug out, to clear the surplus fuel and heat the plug. 

   All good stuff, and thanks to all.

     I must say how I am surprised that I get replies at all times of the day and night. 

        Now, I am away on holiday for a few days so you might not hear from me until next weekend.

[Barnsey]

It's been a while,due to holidays and stuff but a new update.

  I bought a spark tester, which I had to tweek with my dremel to make it fit, but it showed that I was getting a spark when the plug is in the cylinder.

   I tickled the carb, which overran as usual, due to the float sticking, so a tap with a hammer fixed that. 

    Then I took the plug out and spun it over a couple of times to clear any surplus fuel. 

   Plug back in and kick.  One promising cough but that was it.   

   Next I will try pre-heating the plug a bit before kicking, as someone suggested, and I am still seeing 5.5 volts on the coil, so I will look at getting teh full 6V plus.